(a) Technical Field
The present disclosure of invention relates to a display device, and more particularly, to a display device capable of acquiring touch information.
(b) Description of Related Technology
Recently, advancements in display devices have been rapidly developing because flat and/or curved thin panel displays have been explosively capturing the market. Here, the flat and/or curved thin panel display means a display device having a thickness smaller than a size of a conventional CRT (cathode ray tube) screen, and may include as an example, a liquid crystal display (LCD), an organic light emitting diodes display (OLEDD), and the like.
The display device includes a plurality of pixels displaying an image and a driver for driving the plurality of pixels. In order to implement color display, each pixel uniquely displays in an area perceived by the naked eye as no more than a dot, one of primary colors or alternately displays the primary colors rapidly integrated over time so that a desired color is recognized by the spatial and temporal summing of the luminances of the primary colors as performed by the human visual system. An example of the primary colors may include three primary colors such as red, green, and blue. In the case of spatial division, each pixel of the display device may include a color filter or a light emitting member expressing one of the primary colors. A set of pixels expressing the respective primary colors may express full colors together.
The liquid crystal display (LCD) which is one of the most common types of flat (or curved) thin panel displays currently in use, includes two sheets of display panels with field generating electrodes such as a pixel electrode, a common electrode, and the like and a liquid crystal layer interposed therebetween. The liquid crystal display device generates an electric field in the liquid crystal layer by applying voltage to the field generating electrodes, and determines the direction of liquid crystal molecules of the liquid crystal layer by the generated electric field, thus controlling polarization of incident light so as to display images. The field generating electrodes generating the electric field in the liquid crystal layer may be provided on the two display panels, respectively, or alternatively they may be provided on the same display panel.
The liquid crystal display includes a switching element connected to each pixel electrode and a plurality of signal lines such as a gate line and a data line for applying voltage to the pixel electrode by controlling the switching element.
Long axes of liquid crystal molecules of the liquid crystal layer may be characterized as being pre-aligned to be vertical or horizontal to the two display panels while the electric field is not applied to the liquid crystal layer. In order to implement a wide viewing angle in the liquid crystal display, a plurality of domains having different alignment directions of the liquid crystal molecules may be formed in one pixel. In other words, each pixel is subdivided into a plurality of respective areas or domains each having a different liquid crystal orientation obtainable thereat when no drive signal is applied to the pixel.
As such, in the case of a vertical alignment (VA) mode liquid crystal display, a method of forming cutouts or protrusions in the field generating electrodes is included as a means of forming the plurality of domains in one pixel. The plurality of domains may be formed by the above method, by aligning the liquid crystal in a vertical direction to a fringe field by edges of the cutouts or the protrusions and a fringe field formed between the field generating electrodes facing the edges.
As another means of forming the plurality of domains in one pixel, a light alignment method of controlling an alignment direction and an alignment angle of the liquid crystal by irradiating light to a photosensitive alignment layer, a method of extending the field generating electrodes in different directions, or the like is included.
Meanwhile, recently, in the display device, various techniques which display images by acquiring touch information when an external object is touched on a screen of the display device and transmitting image signals to the display device based on the acquired touch information have been actively developed.
It is to be understood that this background of the technology section is intended to provide useful background for understanding the here disclosed technology and as such, the technology background section may include ideas, concepts or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to corresponding invention dates of subject matter disclosed herein.